Length-weight relationship for Potamotrygon wallacei capturada no medio Rio Negro, Barcelos, Amazonia Brasileira

This research aimed to estimate the length-weight ratio (LWR) of the stingray Potamotrygon wallacei, known locally as the cururu, which was caught in streams and lakes in the middle Negro River region, Amazonas, Brazil. The stingrays were captured during the night (from 11 pm to 1 am) near the shores of streams and lakes, through active search using wooden canoes, head lanterns and scoop nets. The samplings were carried out in November 2017 (5 days), February (8 days), March (3 days) and April (2 days) of 2018, totaling 18 days of sampling. The total fresh weight was measured to 0.1 g of accuracy and the disc width to 0.1 cm accuracy. The parameters a and b of the equation W=a.[DW.sup.b] were estimated. This study provides new maximum length data for the cururu stingray. Keywords: cururu stingray, potamotrygonidae, ornamental fish, elasmobranch. Esta pesquisa teve como objetivo estimar a relagao peso-comprimento (LWR) da arraia Potamotrygon wallacei, conhecida localmente como cururu, que foi capturada em igarapes e lagos na regiao do medio Rio Negro, Amazonas, Brasil. As arraias foram capturadas durante a noite (das 23h-1h) nas margens dos igarapes e lagos, por meio de busca ativa utilizando canoas de madeira, lanternas de cabega e pugas. As coletas foram realizadas nos meses de novembro de 2017 (5 dias), fevereiro (8 dias), margo (3 dias) e abril (2 dias) de 2018, totalizando 18 dias de amostragem. Foram medidos o peso fresco total com precisao de 0,01 g e a largura do disco com precisao de 0,1 cm. Os parametros a e b da equagao W= a.[DW.sup.b] foram estimados. Este estudo prover novos dados de comprimento maximo para a arraia cururu. Palavras-chave: arraia cururu, potamotrygonidae, peixe ornamental, elasmobranquio.